177. An owner who ceases permanently to remove petroleum products from an underground tank or who has not removed petroleum products for 2 years or more must comply with section 8.45 of Chapter VIII of the Construction Code (chapter B-1.1, r. 2).
Subject to section 31.51 of the Environment Quality Act (chapter Q-2), the owner may, however, comply only with paragraph 1 of section 8.45 if not more than 5 years have elapsed since petroleum products were last removed from the tank and one of the following tests shows that the tank and piping are leak-proof:
(1) a leak detection test that meets the requirements of the second paragraph of section 8.130 of Chapter VIII of the Construction Code; and
(2) for single or double-wall tanks emptied of any petroleum products, a pressure test using an inert gas performed in compliance with the following requirements:
(a) a safety valve set at not more than 40 kPa capable of discharging the flow from the pressure source must be installed on a tank opening and its operation must be inspected before each test;
(b) the pressure must be measured using a pressure gauge calibrated in units of not more than 1 kPa;
(c) a pressure of at least 30 kPa and not more than 35 kPa must be created inside the tank;
(d) once the temperature has been stabilized and the pressure source removed, the created pressure must be maintained for at least 4 hours; and
(e) in the case of a compartment tank, each compartment must be tested separately, not simultaneously and only when the adjacent compartment is not under pressure.